Curiously, the full-size truck-based GMC Yukon SUV is mechanically identical to the Chevrolet Tahoe, yet it gets a perfect powertrain score while the Chevy only gets a four out of five rating from JD Power. And the Yukon gets just an average JDP rating for body and interior rating, while the Tahoe gets a top rating in that regard. Could Chevy and GMC owners be fussy about different things? As it stands, both models get a top overall JDP reliability score. Consumer Reports, on the other hand, gives the 2014 Yukon a rock-bottom overall reliability rating, but grants both the Chevy and GMC versions top or above average scores for most mechanical issues including the powertrain, so go figure.